Nontoxic vernix compositions and method of producing

ABSTRACT

A protectant composition comprising vernix for a skin curative and skin protectant effect and a method of using the composition. A natural or synthetic vernix is dispersed in an effect amount and is applied to a surface. The method may be used to repel a naturally occurring agent such as water, or a synthetic agent to which exposure may occur, for example, in an occupational setting.

RELATED APPLICATIONS

[0001] This application claims priority from U.S. ProvisionalApplication Ser. No. 60/202,567 filed May 10, 2000, which is aContinuation-In-Part of U.S. patent application Ser. No. 09/447,108filed Nov. 22, 1999, which is a Continuation-In-Part of U.S. patentapplication Ser. No. 09/257,008 filed Feb. 25, 1999, which is aContinuation-In-Part of U.S. patent application Ser. No. 09/033,209, nowU.S. Pat. No. 5,989,577.

FIELD OF THE INVENTION

[0002] The invention relates generally to a therapeutic or prophylacticvernix composition and method.

BACKGROUND OF THE INVENTION

[0003] Skin is one of the largest organs in the body and coverssubstantially the entire body surface. Skin is composed of two mainlayers: the surface epithelium or epidermis which includes the uppermoststratum corneum, and the subjacent connective tissue layer or dermis.The skin has a number of functions such as protecting an organism frominjury and dessication, receiving environmental stimuli, excretingvarious substances, regulating body temperature and helping to maintainwater balance. Because of its quantitative and qualitative importance,substantially intact and healthy skin is crucial not only for the wellbeing of an organism but for its very survival.

[0004] The health and integrity of skin may be compromised by wounds,abrasions, ulcers, burns, infections, irritations, premature birth andother conditions for which normal skin production and repair processesmay be inadequate. For example, acute conditions such as patients whoare burned over a large surface area often require immediate skinreplacement. Less life-threatening but chronic skin problems such asdecubitus ulcers or irritations from diaper rash may progress to moresevere conditions if left untreated or if they occur in a neonate or ageriatric patient. Skin treatments encompass a variety of methods andproducts. These may range from symptomatic treatments such as the use oftopical anti-inflammatory compounds to the use of replacement skin. Forvarious physiological, medical, and other reasons, however, none ofthese treatments meet the desired goal of utilizing the body's ownhealing and repair system to promote and regulate its own skin growthand maturation.

[0005] Exposure of the skin to water over a prolonged time periodproduces deleterious effects on the integrity and condition of the skin,such as maceration and damage to the barrier function of skin. Forexample, long term water exposure is a known cause of dermatitis.Dermatitis, defined as an inflammation of the skin, is a major problemin professions in which a portion of the skin is subject to prolongedwater exposure (the so-called “wet professions”). Soldiers serving intropical climates are also known to suffer from painful swollen feet(“tropical immersion foot”) due to long term water exposure. Suchsituations comprise a large part of occupational medicine and have asignificant economic impact. Thus, there is a need for treatment andprevention of these deleterious effects on the skin.

[0006] Vernix caseosa (vernix) is a naturally occurring skin protectant.Vernix is a lipid rich substance composed of sebum, epidermal lipids,and desquamated epithelial cells that progressively covers the skin ofthe developing fetus, completely surrounded by amniotic fluid, duringthe last trimester of pregnancy.

[0007] Vernix consists of hydrated cells dispersed in a lipid matrix.This lipid matrix undergoes a transition to a more fluid form atphysiological temperatures and with the application of shear forces,such as those encountered with movement. Vernix is a covering for theskin of the fetus that resembles the stratum corneum except that itlacks multiple rigid desmosomal connections. Consequently, vernixexhibits a viscous fluid character, making controlled management and/orapplication to a surface difficult.

[0008] A need thus exists for a formulation that can be applied to abiological surface such as skin for treatment and prevention ofconditions related to skin surface properties.

SUMMARY OF THE INVENTION

[0009] The invention is directed to a method to enhance hydrophobicityof a biological surface by applying a composition of vernix and adispersing agent to the surface. The composition is applied to thesurface, e.g., skin, in an amount effective to enhance hydrophobicity.Vernix, natural and/or synthetic, may be formulated as a cream, alotion, a gel, an ointment, etc.

[0010] The invention is also directed to a method to regulate skinhydration by applying a composition of vernix and a dispersing agent tothe skin in an amount effective to regulate hydration. The method may beused on developing skin, such as wounded skin or skin on a pretermnewborn.

[0011] The invention is also directed to a method to enhance skin repairby regulating the water gradient of skin with a composition of vernixand a dispersing agent in an amount effective to regulate the watergradient. The composition may be used to repair trauma from a physicalor chemical source.

[0012] The invention is also directed to a method to enhancehydrophobicity of a biological surface by applying a vernix film to thesurface in an amount effective to achieve a surface free energy of atleast about 20 dyne/cm. In one embodiment, the vernix is applied in anamount to achieve a surface free energy of about 40 dyne/cm.

[0013] These and other methods and compositions will be apparent inlight of the following drawings, detailed description and examples.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]FIG. 1 is a graph of change of contact angle with time for variousliquids applied to a vernix film.

[0015]FIG. 2A is a graph of dynamic contact angle measurements forvarious liquids applied to a fresh vernix film.

[0016]FIG. 2B is a graph of static contact angle measurements forvarious liquids applied to a fresh vernix film.

[0017]FIG. 2C is a graph of static contact angle measurements forvarious liquids applied to a seven week old vernix film.

[0018]FIG. 2D is a graph of static contact angle measurements forvarious liquids applied to a petrolatum film.

[0019]FIG. 3A is a graph of dynamic contact angle measurements forvarious liquids applied to a fresh vernix film.

[0020]FIG. 3B is a graph of static contact angle measurements forvarious liquids applied to a fresh vernix film

[0021]FIG. 3C is a graph of static contact angle measurements forvarious liquids applied to a seven week old vernix film.

[0022]FIG. 3D is a graph of static contact angle measurements forvarious liquids applied to a petrolatum film.

[0023]FIG. 4 is a histogram comparing the surface free energy of vernix,skin, and petrolatum.

[0024]FIG. 5 is a graph showing percent barrier recovery using variousfilms.

[0025]FIG. 6 is a histogram of the effect of various films on percentbarrier recovery.

[0026]FIG. 7 is a histogram showing various films and the hydration ofskin in contact with those films.

[0027]FIG. 8 is a histogram showing various films and the hydration ofskin in contact with those films.

[0028]FIG. 9 is a graph showing rehydration of vernix.

DETAILED DESCRIPTION

[0029] A protectant composition of tractable vernix is disclosed. Oneprotectant effect is by the action of vernix as a repellant to one ormore agents. The agent may be a natural compound, e.g., water, or apartially or totally synthetic compound, e.g., a fungicide, rodenticide,and/or insecticide. The term “repellent” includes any enhanced degree ofrepellence over that obtained in the absence of the inventivecomposition. While the extent of repellence may be either partial orcomplete, any enhancement over the untreated state is considered animprovement and is included in the invention.

[0030] Application of the composition to the desired surface may beprophylactic, so that the composition is applied to the skin or othersurface before exposure to the agent occurs. Application of thecomposition may be curative, for example, to further protect acompromised skin surface or to provide a protectant surface duringnatural or mediated healing of an exposed skin surface. Application ofthe composition may be protective, for example, to protect a skinsurface should exposure to the agent occur.

[0031] Protectant vernix compositions may contain natural or syntheticvernix. A synthetic vernix composition may be partially or totallysynthetic. Natural vernix was obtained from a newborn infant at the timeof delivery. Vernix comprises about a 10% lipid fraction by weight,about a 10% protein fraction by weight, and about an 80% volatilefraction by weight. The lipid fraction has been reported to compriselecithin and other phospholipids, squalene, waxes, wax esters, sterolesters, diol esters, triglycerides, free sterols and four classes offatty acids ranging in chain length from C₁₂ to C₂₆ (straight chainsaturated, straight chain unsaturated, branched chain saturated, andbranched chain unsaturated). The lipid fraction may contain, with therelative percentages indicated, squalene (9%), aliphatic waxes (12%),sterol esters (33%), diesters (7%), triglycerides (26%), free sterols(9%), and other lipids (4%). The fatty acids within the aliphatic waxesmay be branched and the branched fatty acids may be methylated. Theprotein fraction consists of epidermally derived proteins, primarilykeratin and filaggrin. The protein fraction also contains trace amountsin the range of about micromolar to millimolar concentrations ofregulatory proteins such as epidermal growth factor, and trace amountsof about nanomolar to micromolar concentrations of surfactant proteinsuch as Surfactant A and Surfactant B. The volatile fraction isprimarily water. The rate of evaporation of volatile components isrelatively slow, presumably due to increased energy requirements for thedissociation of hydrogen bonds and for diffusion from the cellularcomponent through the lipid component to change water from the liquid tothe gaseous state. Vernix is an odorless material, indicating theabsence of volatile carbon or nitrogen containing compounds.

[0032] Synthetic vernix may be produced by mixing one part of naturalvernix, removed from an infant at the time of delivery, with any of thefollowing components in the proportions indicated: either about 0.005 toabout 0.05 parts phospholipid, or trace amounts of about nanomolar tomicromolar concentrations of pulmonary surfactant proteins such asSurfactant A and/or Surfactant B, or 5 parts dimethylsulfoxide (DMSO),or 1 part amniotic fluid, or combinations of the above. Alternatively,synthetic vernix may also be produced by combining lipids to compriseabout a 10% fraction of the entire volume, proteins to comprise about a10% fraction of the entire volume, and water to comprise the remainingabout 80% of the entire volume. The following lipid components arecombined in the relative percentages indicated: squalene (9%), aliphaticwaxes (12%), sterol esters (33%), diesters (7%), triglycerides (26%),free sterols (9%), and other lipids (4%). The fatty acids within thewaxes may be branched and the branched fatty acids may be methylated.The protein components, combined to constitute about a 10% fraction, areepidermally derived proteins, primarily keratin and filaggrin, withtrace amounts of about micromolar to millimolar concentrations ofregulatory proteins such as epidermal growth factor, and trace amountsof about nanomolar to micromolar concentrations of surfactant proteinsuch as Surfactant A and Surfactant B.

[0033] In one embodiment, vernix dispersed in a biocompatible liquid wasapplied to a physiologically acceptable support structure in a liquidstate to form a repellent vernix film. A film is defined herein as asurface and/or interfacial covering, in either a liquid or a solidstate, with temperature-dependant properties. Film-forming techniquesinclude but are not limited to spraying, extruding, blowing, pouring,evaporating, coating and painting. The vernix dispersion is presented asdroplets which coalesce to form a film upon encountering the support.

[0034] In an alternate embodiment, a preformed vernix repellent film isapplied to a support. The physiologically acceptable support structureis one that can withstand sterilization, preferably by standardsterilization techniques known to one skilled in the art such asexposure to gamma radiation, autoclaving, and so on. The supportstructure is not limited to a particular composition or configurationand, depending upon its use, may or may not be sterilized and may takevarious forms.

[0035] In another embodiment, the nontoxic vernix film is used toenhance skin cell maturation and may be applied to structures such asfilters, membranes, beads, particles, and so on. Similarly, the supportstructure is not limited to a particular state of matter and may be asolid, a semi-solid, a gel and so on. In one embodiment, the supportconsists of a nylon monofilament interpositional surfacing material suchas Interfaces pads (Winfield Laboratories, Inc., Dallas Tex.), BiobraneII® (Sterling Drug Inc., New York, N.Y.) or circular nylon filters ofsuitable porosity (Micron Separations Inc., Westboro, Mass.). Othersupport materials, however, could also be used to practice theinvention.

[0036] In another embodiment, the nontoxic vernix repellent film is usedto treat or prevent injury due to substance exposure or trauma, and maybe applied to various materials for placement either in direct contactor indirect contact with an exposed skin site. The skin site may beintact (e.g., normal skin) or may be compromised, defined as skin thatis damaged or that lacks at least some of the stratum corneum (e.g.,skin damaged by exposure to the agent in question, another agent, thepresence of a pathological condition such as a rash or contactdermatitis, a physical trauma such as a cut, wound, or abrasion, aunderdeveloped skin such as occurs in a preterm infant, conditions inwhich either all or part of the epidermis is exposed, conditions inwhich part of the dermis has been removed such as partial thicknesswounds encountered in resurfacing procedures such as chemical peels,dermabrasions, and laser resurfacing, etc.).

[0037] The support structure may be permeable to physical and/orchemical agents, and may take a variety of forms, depending upon itspurpose and the extent of the area requiring dressing or treatment. Thenontoxic vernix film may be applied to various synthetics such asthermoplastic films, blown films and breathable films, and variousnatural and synthetic fabric compositions such as woven, non-woven,spun, and stitched fabrics. The invention may be used in a variety ofproducts, examples of which include wound dressings and coverings suchas bandages, tapes, gauze, adhesive products applied for a short or longterm to the skin, ostomy care products, hospital pads such asincontinent pads, absorbent pads, and examination pads, disposable andcloth diapers, and feminine hygiene products such as intralabialdevices.

[0038] At least one role of vernix is to “waterproof” the fetus duringthis critical period of epidermal barrier development, cornification ofthe epidermis to form the stratum corneum, before birth. Infants bornprematurely have little or no stratum corneum barrier, and areessentially born with compromised skin.

[0039] The interaction of exogenous agents, such as water or otheragents, with vernix is related to the nonpolar (dispersive) and polar(nondispersive) components of vernix and the critical surface tension(CST) of vernix. Water has a relatively high CST (72 dynes/cm). Thehydrophobicity (i.e., relatively low CST) of vernix was unanticipated,since about 80% by weight of natural vernix is water. The nonpolarcomponent (lipids) of vernix is substantially higher than the polarcomponent (cells, which contribute proteins), and confers hydrophobicityto vernix since the lipid component is a continuous phase surroundingthe cellular components with which water is associated. In comparison toa known hydrophobic material and skin protectant, petrolatum, which hasan extremely high nonpolar component, the nonpolar component of vernixis only slightly lower. In addition, the CST of both vernix andpetrolatum are comparable. As a result, application of vernix to asurface such as skin, either normal skin or compromised skin (forexample, wounded, abraded, cut, punctured, etc.), would protect thesurface from the effects of water exposure. The waterproofing effectscould be particularly useful during repeated cycles of skin exposure towater followed by drying, such as occurs with health care professionalsperforming repeated hand washings.

[0040] A result of the low CST of vernix is that little interactionbetween vernix and hydrophilic liquids would be expected to occur. Forexample, there would be expected to be little interaction between avernix-treated surface, such as skin or a substrate to which vernix hasbeen provided, that is exposed to an exogenous hydrophilic liquid, suchas water, saline, urine, etc. The low CST of vernix imparts ahydrophobic character to vernix with respect to these liquids, and hencevernix serves as a protectant against the effects of these liquids.

[0041] A surface to which vernix has been applied, either directly orindirectly, and then exposed to nonpolar agents such as oils, would beexpected to be at least somewhat miscible with the lipid component ofvernix. As described in U.S. Pat. No. 5,989,577 and co-pendingapplications U.S. Ser. Nos. 09/257,008, now U.S. Pat. No. 6,113,932, and09/447,108, each of which are expressly incorporated by reference hereinin their entirety, the water in vernix is associated with cells, and thecells are embedded within the lipid material, thus, the lipid componentpresents vernix to the environment. However, if the lipid fraction isremoved either partially or totally by exposure to hydrophobic agents,then the water rich fraction, such as cells, could be exposed to theenvironment. The inventive composition could be regulated to have ahigher polar component and would repel nonpolar agents. This compositionwould be a protectant to nonpolar materials, even after the hydrophobiclipid components were modified through interaction with the environment.

[0042] In the developing fetus, vernix protects the skin by preventingwater surrounding the fetus from removing essential ingredients, such asenzymes, calcium binding proteins, natural moisturizing factors, ions,etc., required for barrier development. In much the same way, a vernixtreated surface such as skin is protected from exogenous water bypreventing removal of essential ingredients from the surface. Forexample, vernix could protect extraction of natural moisturizing factorsin the upper stratum corneum by water.

[0043] Another role of vernix is to protect the developing skin from thedeleterious effects of substances, such as water, urine, and feces,present in utero during gestation. The inventive vernix composition maybe applied to any biological surface whereby a surface energy of about40 dynes/cm is beneficial for repelling exogenous agents. Thus, aneffective amount of vernix is that which achieves a surface free energyof about 40 dynes/cm, to a minimum of about 20 dynes/cm. For example,applying the inventive vernix composition in an effective amount to thediaper area protects this skin from the damaging effects of fecalmaterial. Feces contain protease and lipase enzymes which can damage theskin surface upon contact. Lowering the surface energy of this skinsurface by applying the inventive vernix composition would provideprotection against contact with the water-containing feces.

[0044] The above information will be further appreciated in light of thefollowing Examples.

EXAMPLE I

[0045] To determine the surface characteristics of vernix, for example,its repellant properties, its barrier function, etc., the surface freeenergy (SFE) of vernix was calculated and analyzed for its polar(nondispersive) and nonpolar (dispersive) components using theOwens/Wendt geometric mean method. This was done by measuring thecontact angle (θ) between vernix and various liquids such as benzylalcohol, diiodomethane, glycerol, and water. The critical surfacetension (CST) of vernix was calculated using Zisman plots. The CST ofvernix provides general information of its interaction with liquids.

[0046] Static and dynamic contact angle measurements were performedusing a contact angle goniometer and FTA 200 dynamic contact angleanalyzer (First Ten Angstroms, Portsmouth, Va.), respectively. Liquids(benzyl alcohol, diiodomethane, glycerol, and water) were dispensedusing 24 gauge blunt end stainless steel needles (Kahnetics DispensingSystems, Bloomington, Calif.) for the dynamic contact angle study. Forthe static contact angle measurements, a Microdispenser (Drummond,Broomall, Pa.) was used. Vernix was spread into films using Accura-gateapplicator #12 with a 0.5 inch applicating gate (Cheminstruments,Fairfield, Ohio).

[0047] Vernix was collected from term newborns, pooled (three to fournewborns) and stored at 4° C. in plastic dishes sealed with Parafilm®until use. Vernix was spread into a uniform film over a polycarbonateplate using a mechanical Teflon-coated applicator with a 0.5 inch wideprecision ground gate centered on the edge (Cheminstruments, Fairfield,Ohio). This restricted passage channeled the flow of vernix through thegate while metering the thickness of the applied film. The filmthickness depended upon the depth of the gate and the angle at which theapplicator blade was held. The applicator was held at a 45° angle duringapplication. The film thickness was 3 mils (76.2 μm).

[0048] One drop (5 μl) of the desired liquid was manually dispensedusing a microdispenser onto the vernix film. The contact angle wasmeasured manually 25-30 seconds after the drop was applied using amagnifying telescope. The analysis for each liquid was performed intriplicate, and contact angle values were averaged. The experiment wasperformed on fresh vernix (one week old) and seven week old vernix. Theexperiment was repeated with a film of petrolatum (Witco, Petrolia,Pa.), a widely used hydrocarbon skin protectant derived from petroleum,replacing the vernix film to contrast the results obtained with vernix.The experiments were performed under controlled temperature (24° C.±1°C.) and relative humidity (50%±5%).

[0049] For dynamic contact angle measurements, liquids were preloadedinto a clean 10 ml syringe fitted with a 24 gauge blunt end stainlesssteel needle (internal diameter=0.292 mm). Computer software controlledthe dispensing rate (0.3 μl/sec) and the drop image appeared on thescreen and was captured for image analysis using software provided withthe goniometer.

[0050] About ten images were taken over 300 seconds (at about 0, 0.5,0.75, 1.3, 2.3, 4.2, 7.5, 26, 48, 89, 164, and 304 sec after the dropwas delivered onto the surface) for benzyl alcohol, diiodomethane, andglycerol. For water, ten images were taken over about 560 seconds toinvestigate the possible decline in the contact angle of water overtime.

[0051] The results of the static contact angle for fresh vernix, sevenweek old vernix, and petrolatum are as follows, indicated asmean±standard deviation (SD):

[0052] Contact angle data for fresh and 7-week old vernix and petrolatum7-week old Fresh vernix vernix Petrolatum Angle SD Angle SD Angle SDBenzyl Alcohol 21.8 2.9 19.6 1.6 34.4 3.0 Diiodomethane 36.2 2.1 31.81.8 38.4 2.2 Glycerol 74.3 1.9 74.2 2.3 79.1 2.1 Water 83.5 0.8 — — — —

[0053] Changes of contact angle with time are shown in FIG. 1. Errorsbars indicate the standard deviation of three measurements; one wayANOVA analysis was used for duiodomethane, glycerol, and water, andKruskal-Wallis ANOVA on Ranks was used for benzyl alcohol.

[0054] For benzyl alcohol, glycerol, and water, the drop in contactangle over time was significant (p<0.01). For duiodomethane, the drop incontact angle over time was not significant (p=0.834).

[0055] The change of dynamic contact angle with time (300 sec for benzylalcohol, diiodomethane, and glycerol; 560 sec for water) may be due toliquid evaporation. Evaporation may be a particular problem with highlyvolatile liquids such as benzyl alcohol, and/or extended measurementtime periods such as with water. Shrinking of the drop may change thecontact angle from advancing to receding; receding contact angles aregenerally smaller than advancing contact angles. Alternatively, somemolecular components of vernix may dissolve into the drop during thecontact time between the liquid and the vernix layer, causingcontamination and a decrease in contact angle. With a 5 μl drop ofliquid, any contamination from soluble vernix components could cause asignificant decrease in the surface tension of the liquid and thecontact angle. Still another alternative is that the liquid is absorbedinto the vernix layer, which could explain the absence of a decrease incontact angle with time using diiodomethane, a totally nonpolarhydrophobic liquid.

[0056] The Critical Surface Tension (CST) was obtained by plottingsurface tension of diiodomethane, glycerol, water, and benzyl alcoholversus the cosine of the dynamic contact angle on a fresh vernix film(FIG. 2A), static contact angle on a fresh vernix film (FIG. 2B), staticcontact angle on seven week old vernix (FIG. 2C), and static contactangle on petrolatum (FIG. 2D). Contact angles were measured at 25 secafter dispensing the liquid. Results from measurement of the dynamiccontact angle of water on fresh vernix were fitted into a cubicpolynomial equation and the contact angle was calculated. In all plots,a linear regression line was fitted and the value of surface tension atCos θ=1(θ=0) was calculated from the resulting regression equation,which corresponded to the CST. These data are as follows: CST (dyne/cm)Fresh vernix (dynamic θ) 40.47 Fresh vernix (static θ) 38.65 7-week oldvernix (static θ) 39.80 Petrolatum (static θ) 35.79

[0057] CST is a “wettability index” that indicates the minimum value ofsurface tension needed for a liquid to spread completely (that is, havea contact angle of zero), on a particular surface material. Any liquidwhose surface tension is equal to or less than the CST will make a zerocontact angle (θ=0, Cos θ=1), and will completely spread on the surface,while any liquid having a surface tension greater than the CST will formdrops with a finite contact angle.

[0058] To determine the CST of vernix, Zisman's CST was measured. CST isthen calculated by extrapolating the contact angle data of variousliquids, having a known surface tension on vernix, back to where thecontact angle is zero.

[0059] The following equation was used to categorize vernix into itsdispersive and polar components:W_(a) = γ_(L)(Cos  θ + 1) = 2(γ_(L)^(D)γ_(S)^(D))^(1/2) + 2(γ_(L)^(P)γ_(S)^(P))^(1/2)

[0060] Work of adhesion (W_(a)) is the energy required to break theattraction between like molecules. Rearranged into the formula for astraight line, the equation is:$\frac{\gamma_{L}\left( {{{Cos}\quad \theta} + 1} \right)}{2\left( \gamma_{L}^{D} \right)^{1/2}} = {{\left( \gamma_{S}^{P} \right)\frac{\left( \gamma_{L}^{P} \right)^{1/2}}{\left( \gamma_{L}^{D} \right)^{1/2}}} + \left( \gamma_{S}^{D} \right)^{1/2}}$Y = m  X + b

[0061] The resulting linear regression equation was plotted fordiiodomethane, glycerol, water, and benzyl alcohol of the dynamiccontact angle on a fresh vernix film (FIG. 3A), static contact angle ona fresh vernix film (FIG. 3B), static contact angle on seven week oldvernix (FIG. 3C), and static contact angle on petrolatum (FIG. 3D). Theresults are provided in the following table.

[0062] A summary of surface tension components (Owens/Wendt analysis)γ_(L) ^(D) (dyne/cm) γ_(L) ^(P) (dyne/cm) Total (dyne/cm) Fresh vernix42.16 1.48 43.64 (dynamic θ) Fresh vernix 38.14 1.97 40.11 (static θ)7-week old 43.71 0.18 43.89 vernix (static θ) Petrolatum 40.44 0.0340.47 (static θ)

[0063] For all liquids except the nonpolar diiodomethane, there was asignificant decrease of contact angle with time. These results wereplotted and linear regression was applied to the line. The polar surfacefree energy component of vernix was calculated from the slope (which isequal to the square root of γ_(L) ^(P)). The dispersive surface freeenergy component of vernix was calculated from the intercept (which isequal to the square root of γ_(L) ^(D)).

[0064] The liquid total SFE, liquid polar SFE, and liquid dispersive SFEare known and are as follows: Surface Tension Components (dyne/cm)Liquid Total Dispersive Polar Benzyl 39 30.3 8.7 Alcohol Diiodomethane50.8 50.8 0 Glycerol 64 34 30 Water 72.8 21.8 51

[0065]FIG. 4 is a histogram showing the surface free energy (SFE) indyne/cm of vernix, skin from the forearm, skin from the forehead, andpetrolatum. As shown in FIG. 4, vernix, skin and petrolatum share asimilar total surface free energy value. Vernix, skin and petrolatumalso share a major dispersive component.

[0066] Skin is known for its superior water barrier properties. The CSTof vernix was higher than the CST of skin on both the forearm (27dyne/cm) and the finger (27 dyne/cm), but was lower than the CST of skinon the forehead (50.7 dyne/cm). The forearm, finger, and forehead varyin part due to differences in sebum level, with the forehead possessingthe highest density of sebaceous glands and the highest level of sebumsecretion. The high CST in forehead skin is due to the presence ofsebum. In comparing the CST of forehead skin before and after extractionof sebum, sebum extraction decreased skin wettability and CST valuesfrom 50.7 dyne/cm to 29.3 dyne/cm. Degreasing and cleaning of the skinsurface reduces the skin wettability and CST. The obtained CST forvernix (about 39 dyne/cm) is the approximate average of the CST for thesebum-poor forearm skin (about 27 dyne/cm) and the sebum-rich foreheadskin (about 51 dyne/cm), supporting the lipid composition of vernix as amixture of stratum corneum lipids and sebaceous lipids.

[0067] The CST of vernix is also similar to the CST of several polymers,e.g., vinyl polymers such as polyvinyl chloride (PVC, CST 39 dyne/cm),polyvinyl alcohol (37 dyne/cm), and polyvinylidene chloride (40dyne/cm). A common use for PVC is for waterproofing in raincoats andshower curtains.

[0068] These results indicate that the main component of the vernixsurface free energy was dispersive, that is, nonpolar. Fresh vernixpolar SFE was 1.48 dynes/cm, while petrolatum had almost no polar SPE(0.03 dynes/cm). The polar component of vernix SFE was minimal, and thenonpolar component was substantially higher. The nonpolar component invernix was slightly lower than that of petrolatum, which has anextremely low polar component. There was agreement between the resultsfor fresh vernix from both static and dynamic contact angle data. Theolder vernix sample had comparable results but had a lower polarcomponent, which may represent drying of the sample over seven weeks.

[0069] The CST of fresh vernix, 40.47 dyne/cm, was comparable to the CSTof petrolatum, 35.79 dyne/cm, and did not differ between the two methods(dynamic contact angle and static contact angle). The CST for fresh andolder vernix samples was also comparable. Given the CST, vernix is a lowenergy surface. The low CST of vernix is in contrast to the CST of waterwhich was 72 dyne/cm. Vernix contains about 80% by weight of water.These results indicate that vernix has low surface energy and is highlyunwettable. Although vernix is about 80% water, which is highlyenergetic, the major part of the vernix SFE was hydrophobic(dispersive). The limited contribution of the polar component, limitingthe interaction between vernix and hydrophilic liquids, was unexpectedbut supportive of vernix as a natural protect which waterproofs a fetusthat is continuously exposed to amniotic fluid. Because of the highwater content in vernix, the high hydrophobic component of its surfacefree energy is due to the continuous phase of the lipids around thecellular elements.

EXAMPLE 2

[0070] Barrier repair was evaluated by determining the effect of variousfilms on the rate of barrier repair and the quality of the barrier thatwas formed. The semi-permeable films are used in the health careindustry and include Vigilon® (a high water content hydrogel, 96% water,covered with impermeable plastic), Silon®, Flexzan®, and Exxaire® forthe treatment of compromised skin. The occlusive (control) films wereSaran Wrap® and Teflon® (polyethylene terphthalate). No occlusioncontrols contained no film.

[0071] The Vigilon® film provided a wet, occlusive environment forcompromised skin because the water-rich hydrogel was positioned againstthe compromised skin surface and the plastic backing provided occlusionto water loss, and was damaging to skin due to the high water exposureand complete occlusion.

[0072] The semipermeable films facilitated quantitatively better barrierrecovery of the compromised skin, compared to films that resulted ineither complete occlusion, no occlusion, or a high water environmentplus occlusion. The skin sites that recovered under this semipermeablefilm developed better skin condition relative to the fully occlusivefilm and the no occlusion control film, and provided more favorableenvironment for skin during barrier recovery that the no occlusion filmand the complete occlusion control film. The films that producedintermediate levels of recovered skin hydration had the highest barrierrecovery values. The film created a skin hydration environment thatresults in different rates of barrier repair. The semipermeable filmenhanced the rate of barrier repair. The semipermeable film alsoenhanced the quality of the recovered skin. These enhancements were dueto the semipermeable film facilitating the optimum water vapor gradientduring the recovery process of the compromised skin.

[0073]FIG. 5 shows that the semipermeable films result in a higherpercent barrier than no occlusion and Vigilon®. FIG. 6 shows that thesemipermeable Exxaire® has a significantly higher percent barrierrecovery than no occlusion and the occlusive films. FIG. 7 shows thatVigilon® provided a very high level of water when in contact with theskin. In contrast, the semipermeable films provided an intermediatelevel of hydration. In further contrast, the semipermeable filmsproduced higher hydration than no occlusion. As a result, anintermediate level of hydration provides the optimum environment forbarrier repair to occur, compared to either a high or low level ofhydration. FIG. 8 shows, again, that the semipermeable film Exxaire®provided an intermediate level of hydration, in comparison to noocclusion and to the high hydration produced by the occlusive films.FIG. 9 demonstrates that vernix can be effectively rehydrated whenexposed to water or saline.

[0074] The action of vernix is similar to that of the semipermeablefilm. A vernix film is not fully occlusive. Vernix contains about 80%water and, unlike stratum corneum, it does not have desmosomalattachments between cells and its lipid phase is not as structured as instratum corneum. Therefore, water is transported through vernix in muchthe same way as water vapor is transported through a semipermeable film.Vernix regulates the water or hydration environment of the skin duringrepair, controlling the water environment to which the skin is exposed.Thus, application of vernix to compromised skin provides an optimumwater gradient to the skin surface. The high water content of vernix,associated with the cellular components, provides a supply of water totissues during barrier repair, barrier formation, and compromised skinhealing or repair processes. Vernix also retains its water, and loseswater to the environment only very slowly, as shown in measurements ofweight changes in vernix over time. Thus, vernix provides a source ofwater but also releases some water to the environment.

[0075] Vernix also rehydrates by uptake of water during water exposure.Normal adult skin with vernix applied to the skin surface (treated) hada higher rate of water loss than skin to which no vernix was applied(control), demonstrating that vernix released water from the skinsurface. Measurements of peak sorption indicated that the vernix treatedskin binds water to a significantly greater extent than that ofuntreated skin, and had a significantly higher water binding capacitythan untreated skin. Vernix takes up water from a wet epidermal surface,for example, a skin wound, and moves it away from the surface or wound,for example, into cells. These hydration properties of vernix, bothdehydration and rehydration, allow vernix to function in both wet anddry environments. Vernix accordingly can either give up water, or takeup water, using physiological control mechanisms such as water bindingof proteins and soluble materials in the cells.

[0076] A nontoxic vernix film and methods of producing and using thefilm are thus disclosed. The compositions and methods of the inventionmay be used for providing a biological waterproofing surface. Othervariations or embodiments of the invention will also be apparent to oneof ordinary skill in the art from the above description and example. Forexample, vernix may be formulated into a cream, such as a first aidcream, a cream for treating poison ivy or other forms of contactdermatitis, or a diaper rash cream, or other formulations such as apaste, lotion, gel, ointment, cream, etc. Thus, the forgoing embodimentsare not to be construed as limiting the scope of this invention.

What is claimed is:
 1. A method to enhance hydrophobicity of abiological surface comprising applying a composition consistingessentially of vernix and a dispersing agent to said surface in anamount effective to enhance hydrophobicity of said surface.
 2. Themethod of claim 1 wherein said surface is skin.
 3. The method of claim 1wherein said composition is applied directly to said surface.
 4. Themethod of claim 1 wherein said composition is selected from the groupconsisting of natural vernix, synthetic vernix, and combinationsthereof.
 5. The method of claim 1 wherein said surface is a diaper area.6. The method of claim 1 where said surface is compromised.
 7. Themethod of claim 1 wherein said surface is exposed to an aqueous basedagent.
 8. The method of claim 7 wherein said aqueous based agent iswater.
 9. The method of claim 1 wherein said composition is provided ona physiologically acceptable substrate.
 10. The method of claim 1wherein said composition is provided in a formulation selected from thegroup consisting of a cream, a lotion, a gel, an ointment, andcombinations thereof.
 11. The method of claim 1 wherein said compositionis provided to protect against an occupational agent.
 12. A method toregulate skin hydration comprising applying a composition consistingessentially of vernix and a dispersing agent to skin in an amounteffective to regulate hydration.
 13. The method of claim 12 wherein saidskin is developing skin.
 14. The method of claim 13 wherein saiddeveloping skin is an epidermal surface.
 15. The method of claim 14wherein said epidermal surface is undergoing terminal differentiation toproduce a cornified layer.
 16. The method of claim 13 wherein saiddeveloping skin is a wound.
 17. The method of claim 16 wherein saidregulation comprises wound healing.
 18. The method of claim 13 whereinsaid developing skin is on a newborn.
 19. The method of claim 12 whereinsaid composition regulates hydration by giving up water.
 20. The methodof claim 12 wherein said composition regulates hydration by taking upwater.
 21. The method of claim 12 wherein said composition is regulatedto contain an increased polar component
 22. The method of claim 12wherein said composition is regulated by removing a lipid fraction fromvernix.
 23. A method to enhance skin repair comprising regulating awater gradient of skin by applying a composition consisting essentiallyof vernix and a dispersing agent to said skin in an amount effective toregulate said water gradient.
 24. The method of claim 23 wherein saidcomposition is selected from natural vernix, synthetic vernix, andcombinations thereof.
 25. The method of claim 23 to repair physicaltrauma to said skin.
 26. The method of claim 23 to repair chemicaltrauma to said skin.
 27. A method to enhance hydrophobicity of abiological surface comprising applying a vernix film to said surface inan amount effective to achieve a free energy of at least about 20dyne/cm of said surface.
 28. The method of claim 27 wherein said amountis about 40 dyne/cm.
 29. A method of protecting skin against an agentcomprising providing a protectant composition of tractable vernix tosaid skin in an amount sufficient to enhance repellence of said agentfrom skin.
 30. The method of claim 29 wherein said agent is water. 31.The method of claim 29 wherein said agent is a toxin.
 32. The method ofclaim 29 wherein said agent is selected from the group consisting of afungicide, a rodenticide, an insecticide, and combinations thereof. 33.The method of claim 29 wherein said composition is applied directly toskin.
 34. The method of claim 29 wherein said composition is appliedindirectly to skin.
 35. The method of claim 29 wherein said compositionis applied prophylactically.
 36. The method of claim 29 wherein saidcomposition is applied to intact skin.
 37. The method of claim 29wherein said composition is applied to compromised skin.
 38. The methodof claim 29 wherein said composition comprises vernix selected from thegroup consisting of natural vernix, synthetic vernix, and combinationsthereof.
 39. A method of enhancing a barrier property of skin comprisingproviding a vernix composition to skin to prevent removal of a componentrequired for barrier function.
 40. The method of claim 39 wherein saidcomponent is selected from the group consisting of enzymes, calciumbinding proteins, natural moisturizing factors, ions, and combinationsthereof.
 41. The method of claim 39 wherein said composition protectsskin from extraction of natural moisturizing factors in the upperstratum corneum by water.
 42. A method of protecting skin comprisingproviding a composition consisting essentially of vernix in an amount tolower a critical surface tension of said skin.